drivers/media/usb/usbvision/usbvision-i2c.c

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This source file includes following definitions.
try_write_address
try_read_address
usb_find_address
usbvision_i2c_xfer
functionality
usbvision_i2c_register
usbvision_i2c_unregister
usbvision_i2c_read_max4
usbvision_i2c_write_max4
usbvision_i2c_write
usbvision_i2c_read
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * usbvision_i2c.c
   4  *  i2c algorithm for USB-I2C Bridges
   5  *
   6  * Copyright (c) 1999-2007 Joerg Heckenbach <joerg@heckenbach-aw.de>
   7  *                         Dwaine Garden <dwainegarden@rogers.com>
   8  *
   9  * This module is part of usbvision driver project.
  10  * Updates to driver completed by Dwaine P. Garden
  11  */
  12 
  13 
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/delay.h>
  17 #include <linux/init.h>
  18 #include <linux/uaccess.h>
  19 #include <linux/ioport.h>
  20 #include <linux/errno.h>
  21 #include <linux/usb.h>
  22 #include <linux/i2c.h>
  23 #include "usbvision.h"
  24 
  25 #define DBG_I2C         (1 << 0)
  26 
  27 static int i2c_debug;
  28 
  29 module_param(i2c_debug, int, 0644);                     /* debug_i2c_usb mode of the device driver */
  30 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  31 
  32 #define PDEBUG(level, fmt, args...) { \
  33                 if (i2c_debug & (level)) \
  34                         printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
  35                                 __func__, __LINE__ , ## args); \
  36         }
  37 
  38 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  39                             short len);
  40 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  41                            short len);
  42 
  43 static inline int try_write_address(struct i2c_adapter *i2c_adap,
  44                                     unsigned char addr, int retries)
  45 {
  46         struct usb_usbvision *usbvision;
  47         int i, ret = -1;
  48         char buf[4];
  49 
  50         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
  51         buf[0] = 0x00;
  52         for (i = 0; i <= retries; i++) {
  53                 ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
  54                 if (ret == 1)
  55                         break;  /* success! */
  56                 udelay(5);
  57                 if (i == retries)       /* no success */
  58                         break;
  59                 udelay(10);
  60         }
  61         if (i) {
  62                 PDEBUG(DBG_I2C, "Needed %d retries for address %#2x", i, addr);
  63                 PDEBUG(DBG_I2C, "Maybe there's no device at this address");
  64         }
  65         return ret;
  66 }
  67 
  68 static inline int try_read_address(struct i2c_adapter *i2c_adap,
  69                                    unsigned char addr, int retries)
  70 {
  71         struct usb_usbvision *usbvision;
  72         int i, ret = -1;
  73         char buf[4];
  74 
  75         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
  76         for (i = 0; i <= retries; i++) {
  77                 ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
  78                 if (ret == 1)
  79                         break;  /* success! */
  80                 udelay(5);
  81                 if (i == retries)       /* no success */
  82                         break;
  83                 udelay(10);
  84         }
  85         if (i) {
  86                 PDEBUG(DBG_I2C, "Needed %d retries for address %#2x", i, addr);
  87                 PDEBUG(DBG_I2C, "Maybe there's no device at this address");
  88         }
  89         return ret;
  90 }
  91 
  92 static inline int usb_find_address(struct i2c_adapter *i2c_adap,
  93                                    struct i2c_msg *msg, int retries,
  94                                    unsigned char *add)
  95 {
  96         unsigned short flags = msg->flags;
  97 
  98         unsigned char addr;
  99         int ret;
 100 
 101         addr = (msg->addr << 1);
 102         if (flags & I2C_M_RD)
 103                 addr |= 1;
 104 
 105         add[0] = addr;
 106         if (flags & I2C_M_RD)
 107                 ret = try_read_address(i2c_adap, addr, retries);
 108         else
 109                 ret = try_write_address(i2c_adap, addr, retries);
 110 
 111         if (ret != 1)
 112                 return -EREMOTEIO;
 113 
 114         return 0;
 115 }
 116 
 117 static int
 118 usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
 119 {
 120         struct i2c_msg *pmsg;
 121         struct usb_usbvision *usbvision;
 122         int i, ret;
 123         unsigned char addr = 0;
 124 
 125         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
 126 
 127         for (i = 0; i < num; i++) {
 128                 pmsg = &msgs[i];
 129                 ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
 130                 if (ret != 0) {
 131                         PDEBUG(DBG_I2C, "got NAK from device, message #%d", i);
 132                         return (ret < 0) ? ret : -EREMOTEIO;
 133                 }
 134 
 135                 if (pmsg->flags & I2C_M_RD) {
 136                         /* read bytes into buffer */
 137                         ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
 138                         if (ret < pmsg->len)
 139                                 return (ret < 0) ? ret : -EREMOTEIO;
 140                 } else {
 141                         /* write bytes from buffer */
 142                         ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
 143                         if (ret < pmsg->len)
 144                                 return (ret < 0) ? ret : -EREMOTEIO;
 145                 }
 146         }
 147         return num;
 148 }
 149 
 150 static u32 functionality(struct i2c_adapter *adap)
 151 {
 152         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 153 }
 154 
 155 /* -----exported algorithm data: -------------------------------------  */
 156 
 157 static const struct i2c_algorithm usbvision_algo = {
 158         .master_xfer   = usbvision_i2c_xfer,
 159         .smbus_xfer    = NULL,
 160         .functionality = functionality,
 161 };
 162 
 163 
 164 /* ----------------------------------------------------------------------- */
 165 /* usbvision specific I2C functions                                        */
 166 /* ----------------------------------------------------------------------- */
 167 static const struct i2c_adapter i2c_adap_template;
 168 
 169 int usbvision_i2c_register(struct usb_usbvision *usbvision)
 170 {
 171         static unsigned short saa711x_addrs[] = {
 172                 0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
 173                 0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
 174                 I2C_CLIENT_END };
 175 
 176         if (usbvision->registered_i2c)
 177                 return 0;
 178 
 179         usbvision->i2c_adap = i2c_adap_template;
 180 
 181         snprintf(usbvision->i2c_adap.name, sizeof(usbvision->i2c_adap.name),
 182                  "usbvision-%d-%s",
 183                  usbvision->dev->bus->busnum, usbvision->dev->devpath);
 184         PDEBUG(DBG_I2C, "Adaptername: %s", usbvision->i2c_adap.name);
 185         usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
 186 
 187         i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
 188 
 189         if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
 190                 printk(KERN_ERR "usbvision_i2c_register: can't write reg\n");
 191                 return -EBUSY;
 192         }
 193 
 194         PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
 195         PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
 196 
 197         /* register new adapter to i2c module... */
 198 
 199         usbvision->i2c_adap.algo = &usbvision_algo;
 200 
 201         usbvision->i2c_adap.timeout = 100;      /* default values, should       */
 202         usbvision->i2c_adap.retries = 3;        /* be replaced by defines       */
 203 
 204         i2c_add_adapter(&usbvision->i2c_adap);
 205 
 206         PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
 207 
 208         /* Request the load of the i2c modules we need */
 209         switch (usbvision_device_data[usbvision->dev_model].codec) {
 210         case CODEC_SAA7113:
 211         case CODEC_SAA7111:
 212                 /* Without this delay the detection of the saa711x is
 213                    hit-and-miss. */
 214                 mdelay(10);
 215                 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 216                                 &usbvision->i2c_adap,
 217                                 "saa7115_auto", 0, saa711x_addrs);
 218                 break;
 219         }
 220         if (usbvision_device_data[usbvision->dev_model].tuner == 1) {
 221                 struct v4l2_subdev *sd;
 222                 enum v4l2_i2c_tuner_type type;
 223                 struct tuner_setup tun_setup;
 224 
 225                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 226                                 &usbvision->i2c_adap,
 227                                 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
 228                 /* depending on whether we found a demod or not, select
 229                    the tuner type. */
 230                 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 231 
 232                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 233                                 &usbvision->i2c_adap,
 234                                 "tuner", 0, v4l2_i2c_tuner_addrs(type));
 235 
 236                 if (sd == NULL)
 237                         return -ENODEV;
 238                 if (usbvision->tuner_type != -1) {
 239                         tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
 240                         tun_setup.type = usbvision->tuner_type;
 241                         tun_setup.addr = v4l2_i2c_subdev_addr(sd);
 242                         call_all(usbvision, tuner, s_type_addr, &tun_setup);
 243                 }
 244         }
 245         usbvision->registered_i2c = 1;
 246 
 247         return 0;
 248 }
 249 
 250 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
 251 {
 252         if (!usbvision->registered_i2c)
 253                 return 0;
 254 
 255         i2c_del_adapter(&(usbvision->i2c_adap));
 256         usbvision->registered_i2c = 0;
 257 
 258         PDEBUG(DBG_I2C, "i2c bus for %s unregistered", usbvision->i2c_adap.name);
 259 
 260         return 0;
 261 }
 262 
 263 static int
 264 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
 265                      char *buf, short len)
 266 {
 267         int rc, retries;
 268 
 269         for (retries = 5;;) {
 270                 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
 271                 if (rc < 0)
 272                         return rc;
 273 
 274                 /* Initiate byte read cycle                    */
 275                 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
 276                 /*                    d3 0=Wr 1=Rd             */
 277                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 278                                       (len & 0x07) | 0x18);
 279                 if (rc < 0)
 280                         return rc;
 281 
 282                 /* Test for Busy and ACK */
 283                 do {
 284                         /* USBVISION_SER_CONT -> d4 == 0 busy */
 285                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 286                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 287                 if (rc < 0)
 288                         return rc;
 289 
 290                 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
 291                 if ((rc & 0x20) == 0)   /* Ack? */
 292                         break;
 293 
 294                 /* I2C abort */
 295                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 296                 if (rc < 0)
 297                         return rc;
 298 
 299                 if (--retries < 0)
 300                         return -1;
 301         }
 302 
 303         switch (len) {
 304         case 4:
 305                 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
 306                 /* fall through */
 307         case 3:
 308                 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
 309                 /* fall through */
 310         case 2:
 311                 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
 312                 /* fall through */
 313         case 1:
 314                 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
 315                 break;
 316         default:
 317                 printk(KERN_ERR
 318                        "usbvision_i2c_read_max4: buffer length > 4\n");
 319         }
 320 
 321         if (i2c_debug & DBG_I2C) {
 322                 int idx;
 323 
 324                 for (idx = 0; idx < len; idx++)
 325                         PDEBUG(DBG_I2C, "read %x from address %x", (unsigned char)buf[idx], addr);
 326         }
 327         return len;
 328 }
 329 
 330 
 331 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
 332                                  unsigned char addr, const char *buf,
 333                                  short len)
 334 {
 335         int rc, retries;
 336         int i;
 337         unsigned char *value = usbvision->ctrl_urb_buffer;
 338         unsigned char ser_cont;
 339 
 340         ser_cont = (len & 0x07) | 0x10;
 341 
 342         value[0] = addr;
 343         value[1] = ser_cont;
 344         for (i = 0; i < len; i++)
 345                 value[i + 2] = buf[i];
 346 
 347         for (retries = 5;;) {
 348                 rc = usb_control_msg(usbvision->dev,
 349                                      usb_sndctrlpipe(usbvision->dev, 1),
 350                                      USBVISION_OP_CODE,
 351                                      USB_DIR_OUT | USB_TYPE_VENDOR |
 352                                      USB_RECIP_ENDPOINT, 0,
 353                                      (__u16) USBVISION_SER_ADRS, value,
 354                                      len + 2, HZ);
 355 
 356                 if (rc < 0)
 357                         return rc;
 358 
 359                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 360                                       (len & 0x07) | 0x10);
 361                 if (rc < 0)
 362                         return rc;
 363 
 364                 /* Test for Busy and ACK */
 365                 do {
 366                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 367                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 368                 if (rc < 0)
 369                         return rc;
 370 
 371                 if ((rc & 0x20) == 0)   /* Ack? */
 372                         break;
 373 
 374                 /* I2C abort */
 375                 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 376 
 377                 if (--retries < 0)
 378                         return -1;
 379 
 380         }
 381 
 382         if (i2c_debug & DBG_I2C) {
 383                 int idx;
 384 
 385                 for (idx = 0; idx < len; idx++)
 386                         PDEBUG(DBG_I2C, "wrote %x at address %x", (unsigned char)buf[idx], addr);
 387         }
 388         return len;
 389 }
 390 
 391 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 392                             short len)
 393 {
 394         char *buf_ptr = buf;
 395         int retval;
 396         int wrcount = 0;
 397         int count;
 398         int max_len = 4;
 399 
 400         while (len > 0) {
 401                 count = (len > max_len) ? max_len : len;
 402                 retval = usbvision_i2c_write_max4(usbvision, addr, buf_ptr, count);
 403                 if (retval > 0) {
 404                         len -= count;
 405                         buf_ptr += count;
 406                         wrcount += count;
 407                 } else
 408                         return (retval < 0) ? retval : -EFAULT;
 409         }
 410         return wrcount;
 411 }
 412 
 413 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 414                            short len)
 415 {
 416         char temp[4];
 417         int retval, i;
 418         int rdcount = 0;
 419         int count;
 420 
 421         while (len > 0) {
 422                 count = (len > 3) ? 4 : len;
 423                 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
 424                 if (retval > 0) {
 425                         for (i = 0; i < len; i++)
 426                                 buf[rdcount + i] = temp[i];
 427                         len -= count;
 428                         rdcount += count;
 429                 } else
 430                         return (retval < 0) ? retval : -EFAULT;
 431         }
 432         return rdcount;
 433 }
 434 
 435 static const struct i2c_adapter i2c_adap_template = {
 436         .owner = THIS_MODULE,
 437         .name              = "usbvision",
 438 };
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/media/usb/usbvision/usbvision-i2c.c

DEFINITIONS
